A ski binding of the abovementioned type, in which the ski binding parts are mounted on a plate, is described for example in German OS No. 2,221,105. In this known device the locking members act against a release toward the side either only in the front or only in the rear, however, against a release upwardly both in front and also in the rear. However, the boot is released only after the plate is completely separated from the ski and the ski boot and the plate are released together from the ski. This has the disadvantage that the plate must move through a relatively large toggle lever range until it is released by the locking members and can release from the ski. The resulting time delays can possibly be disadvantageous with respect to the safety, particularly at very high skiing speeds in which a delay of the release mechanism can occur. Therefore, in the known ski binding, the initial tension of the spring which effects the release is adjusted in consideration of these circumstances. The more rigid spring adjustment in turn has the consequence that a release will possibly occur in response to high impact forces, which with a further adjustment or initial tension of the springs would still lie in the elastic range of the binding.
An improved heel holder for a ski binding of the abovementioned type is described in U.S. Pat. No. 4,003,603. In this construction, the locking member is provided on the plate, the holding member on the ski, wherein, as is actually known, the one holder can be moved relative to the plate, which holder is held in the downhill position by a control member which is associated with the locking member, which control member releases the holder after movement of the rear plate end a certain degree, which holder releases the boot and subsequently under the action of the spring which loads the locking member pivots the plate about the pivot bearing back into its initial position and holds it on the ski.
The just now described construction has the disadvantage, that the heel holder always opens up upwardly, regardless of whether the outside forces which act on the plate cause a release upwardly, to the side or diagonally. This has the disadvantage that the forces which do not fall in direction of the direct release suffer a loss in the form of additional friction, so that only the associated vector of the power parallelogram prevails. Another disadvantage of the known construction is that a subsequent and/or separate adjustment of the actual heel holder to the boot is not possible, because the holder and the locking member are adjusted constantly to one another.
The purpose of the invention is to overcome the mentioned disadvantages and to design a heel holder of the abovementioned safety ski binding such that between the heel holder and the clamped-in ski boot there can be assured a separate and possibly adjustable thrust adjustment.
In addition, the invention is to facilitate the use of the aforedescribed measure also in the case of a heel holder, namely without the use of a sole plate or the like. Finally the plate is supposed to be able to be replaced also with a differently designed holding element in order to reduce the weight of the safety ski binding.
The set purpose is attained according to the invention by arranging a pin on a movable part of the locking member. One end of a connecting element engages the pin, the other end thereof being connected through a joint to a spring-loaded lock which fixes the heel holder in the tensioned position (in the downhill position), and which lock is pivotally supported on an axle which extends at a right angle to the longitudinal axis of the ski and in the downhill position substantially parallel to the upper side of the ski and which is arranged on or in a housing part of the locking member. The possibly provided sole plate, as is actually known, is to be secured in its front area against a lifting off from the ski while being swingable or liftable from the ski approximately in the center area about a ski-fixed pin.
The inventive construction of the safety ski binding produces particularly advantageous friction conditions for the release operation, because the lock is pivotally supported and by providing a connecting element between the lock and the carrier, a speed ratio is produced which is favorable for the release operation and which can be changed to a limited degree. In addition, the invention facilitates the use of the heel holder both in connection with a sole plate or the like and also the heel holder by itself.
It is thereby possible to form the sole plate, if provided, inventively by a pair of parallel rods which extends in longitudinal direction of the ski and which is supported swingably upwardly at the two front free ends in a ski-fixed mounting member and is held in the rear area by the housing of the locking member. A web member is connected between the two rods and has a bearing which operatively functions with a ski-fixed pin. In this manner, the effect which is achieved by using a sole plate is met in totality, the weight of the entire ski binding is, however, reduced. Using the pair of rods permits, in addition, a particularly simple development of an adjustable front jaw.
In a further development of this thought of the invention, the pair of rods may have teeth thereon, along which a conventional adjusting bridge is longitudinally guided, adjustably and releasably lockable. According to a further thought of the invention, it is possible to arrange in the adjusting bridge a multiply bent spring wire which forms the front jaw, the free ends of which spring wire are anchored in the adjusting bridge at least through a double bent section, so that the spring wire has an initial tension. The spring wire has in the area which is associated with the tip of the ski boot on both sides a further, preferably double (approximately S-shaped) bent section, which is constructed offset rearwardly (toward the heel of the boot) in relationship to the tip of the boot. In this manner the ski boot is held resiliently and laterally supported through a holder which is designed as short as possible limited to some millimeter in longitudinal direction of the ski. The springiness is less at any rate than the overlap of the holder on the heel of the boot .